This patch added a function tcmu_pr_info_encode() which can encode Persistent Reservation info, from a struct tcmu_pr_info to a string, so that we can store this string on a TCMU device. This function will call the pervious added encoder like tcmu_pr_info_reg_encode() to do it's work.
Signed-off-by: Zhu Lingshan <[email protected]> --- drivers/target/target_core_user.c | 133 ++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 0f8eeed61c60..957e444d853b 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -107,6 +107,31 @@ #define TCMU_PR_INFO_XATTR_FIELD_NUM_REGS 5 #define TCMU_PR_INFO_XATTR_FIELD_REGS_START 6 +/* don't allow encoded PR info to exceed 8K */ +#define TCMU_PR_INFO_XATTR_MAX_SIZE 8192 + +#define TCMU_PR_INFO_XATTR_ENCODED_SCSI2_RSV_MAXLEN \ + (TCMU_PR_IT_NEXUS_MAXLEN + sizeof("\n")) + +#define TCMU_PR_INFO_XATTR_ENCODED_PR_RSV_MAXLEN \ + ((sizeof("0x") + sizeof(u64) * 2) + sizeof(" ") + \ + TCMU_PR_IT_NEXUS_MAXLEN + sizeof(" ") + \ + (sizeof("0x") + sizeof(u64) * 2) + sizeof("\n")) + +#define TCMU_PR_INFO_XATTR_ENCODED_PR_REG_MAXLEN \ + ((sizeof("0x") + sizeof(u64) * 2) + sizeof(" ") + \ + TCMU_PR_IT_NEXUS_MAXLEN + sizeof("\n")) + +#define TCMU_PR_INFO_XATTR_ENCODED_MAXLEN(_num_regs) \ + ((sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \ + (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \ + TCMU_PR_INFO_XATTR_ENCODED_SCSI2_RSV_MAXLEN + \ + (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \ + TCMU_PR_INFO_XATTR_ENCODED_PR_RSV_MAXLEN + \ + (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \ + (TCMU_PR_INFO_XATTR_ENCODED_PR_REG_MAXLEN * _num_regs) + \ + sizeof("\0")) + static u8 tcmu_kern_cmd_reply_supported; static struct device *tcmu_root_device; @@ -2304,6 +2329,114 @@ static int tcmu_pr_info_get(struct tcmu_dev *udev, return rc; } +static int tcmu_pr_info_encode(struct tcmu_pr_info *pr_info, + char **_pr_xattr, int *pr_xattr_len) +{ + struct tcmu_pr_reg *reg; + char *pr_xattr; + char *p; + size_t buf_remain; + int rc; + int i; + + if (pr_info->vers != TCMU_PR_INFO_XATTR_VERS) { + pr_err("unsupported PR info version: %u\n", pr_info->vers); + return -EINVAL; + } + + buf_remain = TCMU_PR_INFO_XATTR_ENCODED_MAXLEN(pr_info->num_regs); + if (buf_remain > TCMU_PR_INFO_XATTR_MAX_SIZE) { + pr_err("PR info too large for encoding: %zd\n", buf_remain); + return -EINVAL; + } + pr_debug("encoding PR info: vers=%u, seq=%u, gen=%u, num regs=%u ", + pr_info->vers, pr_info->seq, pr_info->gen, pr_info->num_regs); + pr_debug("into %zd bytes\n", buf_remain); + + pr_xattr = kmalloc(buf_remain, GFP_KERNEL); + if (!pr_xattr) + return -ENOMEM; + + p = pr_xattr; + rc = tcmu_pr_info_vers_seq_encode(p, buf_remain, pr_info->vers, + pr_info->seq); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + + rc = tcmu_pr_info_scsi2_rsv_encode(p, buf_remain, pr_info->scsi2_rsv); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + + rc = tcmu_pr_info_gen_encode(p, buf_remain, pr_info->gen); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + + rc = tcmu_pr_info_rsv_encode(p, buf_remain, pr_info->rsv); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + + rc = tcmu_pr_info_num_regs_encode(p, buf_remain, pr_info->num_regs); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + + i = 0; + list_for_each_entry(reg, &pr_info->regs, regs_node) { + rc = tcmu_pr_info_reg_encode(p, buf_remain, reg); + if (rc < 0) { + rc = -EINVAL; + goto err_xattr_free; + } + + p += rc; + buf_remain -= rc; + i++; + } + + if (i != pr_info->num_regs) { + pr_err("mismatch between PR num_regs and list entries!\n"); + rc = -EINVAL; + goto err_xattr_free; + } + + *_pr_xattr = pr_xattr; + /* +1 to include null term */ + *pr_xattr_len = (p - pr_xattr) + 1; + + pr_err("successfully encoded all %d PR regs into %d bytes: %s\n", + pr_info->num_regs, *pr_xattr_len, pr_xattr); + + return 0; + +err_xattr_free: + kfree(pr_xattr); + return rc; +} + static int tcmu_configure_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); -- 2.17.1
